The invention relates to a drive train, in particular of a motor vehicle having a drive engine, comprising a main output shaft by means of which drive wheels or another assembly can be driven; having a hydrodynamic retarder comprising a driven bladed primary wheel and a bladed secondary wheel which is fixed or driven in the opposite direction to the primary wheel, said wheels forming with one another a toroidal working space which is filled or can be filled with a working medium, in order to transmit torque hydrodynamically from the primary wheel to the secondary wheel; the drive engine has a secondary output shaft by means of which the primary wheel of the retarder is driven. The invention is characterized in that the hydrodynamic retarder is embodied as a single-stage, uncontrolled retarder which can be switched exclusively between a switched-on state and a switched-off state.